Digital images can be captured using a digital image capture device, such as a digital camera. Alternatively, a film scanner can be used to convert a visual image into a digital image. The digital image can be manipulated using computer software, with the manipulation of the digital image including zooming, cropping, and image magnification whereby the original image is converted into an output image intended for an output image product. The output image product can be a hardcopy print produced by means of an appropriate printer, such as an optical printer, digital printer, ink jet printer, thermal printer, or other known printer system. The output image product can also be a mug, tee-shirt, CD, or other product comprising an image.
The output image product is dependent on several factors, including the film scanner resolution, the resolution of the digital image capture device, the resolution of the output device, and the output image product being produced. In addition, the original image in its manipulated form is displayed on a computer monitor or display. This displayed image is dependent on the resolution of the display, and may not be an accurate representation of the output image product.
It is often not apparent to a user of image processing software what selection of image processing parameters (i.e., zoom, crop, magnification) will cause the resultant output image product to be degraded to the point at which the reproduced image is considered unsatisfactory; at least not until the output image product is produced, at which time the output media is wasted and the user is dissatisfied with the service. Nor does the unsatisfactory appearance of the output image product give any indication to the user that an alternative image parameter setting can produce a satisfactory output image product.
It is known that images which reside on negatives of known formats require known magnifications to produce standard size photographic prints. U.S. Pat. No. 6,018,397 (Cloutier et al.) discloses an apparatus and method for providing to a user an assessment of hardcopy output image quality by establishing a boundary level of acceptable hardcopy print quality level based on selected image print size and printing magnification. While this apparatus and method has achieved certain degrees of success in particular applications, the apparatus and method is based on a grain and sharpness model of photographic negatives of a known input format, such as 110 and 35 mm.
In addition, content specific user preferences need to be accounted for. That is, while an image may appear unacceptable to a disinterested third party, the same image may be more than satisfactory to a user of the image due to the content of the image.
With digital images, the digital image data may or may not be available in a known or standard format. For example, an enlargement from a mega-pixel digital camera will most likely differ in quality than an enlargement from a low resolution digital camera at VGA quality.
In addition, the digital image processing history may not be known. That is, the digital image may have been previously digitally manipulated, for example, by limiting the color palette or by compressing the file in a manner that is not visually lossless. Artifacts may be incorporated into the image as a byproduct of the compression technique. Accordingly, it may be difficult to provide a numerical evaluation of “quality” as the system may not be able to assess/comprehend the extent of the manipulations previously made as compared to the original image.
Still further, the resolution of the output device can affect the perceived quality of the output image product. The output device may also limit the output size without replicating or modifying the original image, for example, by pixel replication, padding, enhancement, or interpolation.
Yet further, another factor is the subject matter of the digital image. For example, in certain circumstances, a poor quality reproduction may be preferred to none at all. For example, when the user has strong emotional ties with an image because of the subject matter of the image. In addition, a poor quality reproduction may be the wish of the user if the desire is to convey comedic effect.
Accordingly, a need continues to exist for a system and method of processing a digital image for user assessment of an output image product which recognizes that the appreciation of image quality may differ between users. Such a system and method should be suitable for images scanned from a film negative, images captured digitally, and images which may have been previously digitally manipulated. The system and method needs to recognize that the selected output format has an effect on image quality. The system and method should be suitable for an imaging device (such as a Kodak Picture Maker manufactured by Eastman Kodak Company) as well as a digital image capture device such as a digital camera.